201366690121 has 9 divisors (see below), whose sum is σ = 202683270279. Its totient is φ = 200058615936.

The previous prime is 201366690079. The next prime is 201366690193. The reversal of 201366690121 is 121096663102.

The square root of 201366690121 is 448739.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 187285545225 + 14081144896 = 432765^2 + 118664^2 .

It is not a de Polignac number, because 201366690121 - 2⁹ = 201366689609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201366690221) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 73143081 + ... + 73145833.

Almost surely, 2^201366690121 is an apocalyptic number.

201366690121 is the 448739-th square number.

201366690121 is the 224370-th centered octagonal number.

It is an amenable number.

201366690121 is a deficient number, since it is larger than the sum of its proper divisors (1316580158).

201366690121 is an frugal number, since it uses more digits than its factorization.

201366690121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5832 (or 2916 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 37.

The spelling of 201366690121 in words is "two hundred one billion, three hundred sixty-six million, six hundred ninety thousand, one hundred twenty-one".